Sampling tube



Dec. 13, 1932. IA. STEIN ET AL SAMPLING TUBE Filed Feb. 4, 1932 2 Sheets-Sheet J.

INVENTORS %2% @W a;

De;13,1932. A, ST ETAL 1,890,592

SAMPLING TUBE Filed Feb. 4, 1952 2 Sheets-Sheet .2

lll I v1,1111lpllzlzrrzlrllnllllllr /IIIIIIIIIIIIIIIIIII INVENTORS Fatented Dec. 13, 1932 UNITED STATESv JOSEPH A. STEIN, OF PITTSBURGH, AND LOUIS L. VAYDA, 0F ASPINWALL, PENNSYL-I PATENT OFFICE VANIA, ASSIGNORS TO BACHARACH INDUSTRIAL INSTRUMENT COMPANY, A GOR- PORATION OF PENNSYLVANIA SAMPLING TUBE Application filed February 4, 1932. Serial No. 590,915.

The invention relates to sampling tubes for use in the periodic or continuous analysis of gaseous products in furnaces, kilns and fines. It is common to withdraw a gas sampleby a small diameter pipe, either open at its free end, or capped with a filtering device, such pipe being usually installed in an approximately horizontal position with a slight inclination to providefor the drainage of any condensation. Vhere Very high temperatures ex st in the furnace or fines in which the sampling tube is installed, difliculties attend the use of the device and often prohibit the use of a filtering device at the free end of the tube. The present invention has for its principal objects the provision of an improved tube construction, which will always permit the use of the filtering device regardless of high temperature conditions, and which will function in an enduring man ner, under conditions of high temperature, dirty gases, dirt or dust carried thereby and excessive moisture content. Certain embodiments of the invention are illustrated in the accompanying drawings, wherein:

Figure 1 is a partial side elevation and partial section through the apparatus. Figs. 2, 3, 4, 5 and 6 are sections respectively on the lines IIII, IIITII, IV-IV, VV and VIVI respectively of Fig. 1. Fig. 7 is a partial section and partial side elevation showing a modification; And Fig. 8 is a section on the line VIIIVIII of Fig. 7.

Referring first to the construction of Figs. 1 to 6, the numeral 1 indicates the tube for collectng gas provided at the end with the usual cap 2 of porous filtering material to permit the passage of the gas to be sampled and exclude dust and dirt, such tube being connected at its rear end to the fitting 3 provided with the connections 4 and 5, one of which acts to drain away any condensation in the tube and the other of which is connected to an aspirator for withdrawing the gas. The fitt ng 3 is secured to'a flange 6 which is welded to the rear end of the casing 7 which acts to protect the sampling tube. The casing is provided with a flange 8 welded thereto and adapted to fit against the wall of the furnace or fine carrying the gas to be sampled and provided with the holes, as indicated in Fig. 2 for the passage of bolts or scrialws for fastening the flange to the furnace wa The casing is of U-shape in cross section, as shown in Figs. 8 to 5, with afiat bottom 9 cut away at two points to provide the openings 10 and 11. It is also provided with three downwardly projecting battles 12, 13 and 14: and with a hollow cap 15 welded to the end of the casing.

The casing is supplied with cooling water by means of the pipes 16, 16 lying along the bottom of the casing and preferably welded in position, such pipes leading through the front wall 1'? of the cap 15 (Fig. 6) and contion 18 (Fig. 2). The front end of the casing is provided with a second wall 19 Welded at its edges to the casing 7 The space 20 between the two walls is connected to the hollow space in the cap 15 by means of the slots 21, 21, 21 (Figs. 1 and 6). The rear end of the space is provided With an outlet passage 22 leading into the conduit 22 extending to the rear along the upper wall of the casing 7, and connected at its rear end to the outlet pipe 23. The wall of the conduit is in the form of a U- shaped shell 24 welded at its edges to the casing. Means are thus provided for circulating a cooling flow of waterthrough the casing The main cooling effect is secured at the front end of the casing due to the chamber 20 and the hollow cap 15, which is desirable, as the greatest protection from heat and corrosion is required at this point. The remainder of the casing is cooled sui'liciently by the pipes 16, 16 and the conduit 22 to prevent mechanical weakness and susceptibility to corrosive and erosive action of the gases and suspended matter, but such cooling is insufficient to cause condensation of moisture from gases inside or outside the casing.

A. portion of the gaseous products of combustion, traveling as indicated by the arrow a due to the draft action of a stack or fan, impinge on the plate 12 creating an impact pressure at the point 11, where the bottom plate of the casing is cut away. 7 Certain other portions of the gases, traveling to the right (Fig. 1), indicated by the arrow 6, create a suction eifect along the under side of the casing in the region 10 where the bottom plate of the casing is cut away to expose the inside of the casing to the negative pressure created. Thus a small portion of the gases is diverted through the casing due to the difference in pressure at 10 and 11.

The water cooled cap 15 prevents much of the dust and suspended matter in the gases from entering the casing at 11. The casing sides are extended downward, as indicated in Figs. 4 and 5, to form flanges which add to the stiffness of the casing and also prevent liquid or semi-liquid depositions on the easing from entering or closing the openings 10 and 11. v

The hot gases entering the casing at the point 11 are partially cooled by the water cooled surfaces encountered and prevent high temperatures detrimental to the normal operation or life of the porous refractory filter 2. This filter, at the same time, is prevented from cooling excessively due to radiation from the adjacent uncooled portions of the casing 1. As the gas flows past the filter, a very small sample is diverted through the porous filter walls and through the sampling tube 1 to the outside by aspiration or other means. The minute, pores of the filter permit only the gas to pass, dust and suspended matter being excluded. Most of the gases which enter at 11 leave at 10.

The tube is installed sloping upward, so that any condensed moisture in the sampling tube drains outward. 'The cooling water enters the casing and runs most of its length through the pipes 16, 16, which empty into the chamber 20 at the free end of the casing. The return flow through the conduit 22 and pipe 23 may be utilized to actuate a contact making switch for operating a signaling device when the water becomes too hot. The pipes 16 and the walls of the conduit 22 welded to the casing walls add materially to their resistance against bending.

In'the modification of Fig. 7, the construction follows that of Figs. 1 to 6, except that the cooling means are omitted. In this construction, 25 is the sampling tube, 26 is the porous filtering cap at the outer end of the tube, and 27 is the protecting casing of metal provided with the cap 28 and the openings 29 and 30 corresponding to the openings 10 and 11 of Fig. 1. The rear end of the casing is closed by the-plate 6a carrying the fitting 3, which carries the sampling tube, and corresponding to the construction in Fig. 1 bearing the same reference numerals. The bafiies 31, 32 and 33 at the outer endsof the openings 29 and 30 correspond in function with the baflies of Fig. 1 at the ends of the openings 10 and 11. The flange 34 welded to the casing 27 corresponds to the flange 8 of Fig. 1. In this construction a mud-shield-33a of inverted U-shape in cross section fits over and is welded to the casing 27. This shield adds stiffness to the casing, and assists in preventing foreign matter from entering the casing through the sides of the openings 29 and 30 which are formed by cutting out segments of the casing 27.

What we claim is:

1, In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, and baflling means projecting laterally from the casing for promoting a flow of gases through the portion of the casing between the two open ings. 1

2. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, and a baitle plate projecting from the casing adjacent the inner end of the outer opening.

3. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, a baffle plate projecting from the casing adjacent the inner end of the outer opening, and a second bafiie plate projecting from the casing adjacent the outer side of the inner opening.

4. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, a baffle plate projecting from the casing adjacent the inner end of the outer opening, and a pair of bafiie plates projecting from the casing adjacent the inner opening, one at the outer end thereof and the other at the inner end thereof.

5. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, a water cooled bafiie projecting from the casing at the outer end of the outer opening, and a second bafiie projecting from the casing at the inner end of such opening.

6. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surpan rounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, means for water cooling the casing throughout its length but to a much greater extent for that portion of the casing outward of the filter than for the portion of the casing inward of the filter, and bafliing means projecting laterally from the casing for promoting a flow of gases through the portion of the casing between the opening.

7. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing sur rounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, means for water cooling the casing throughout its length but to a much greater extent for that portion of the casing outward of the filter than for the portion of the casing inward of the filter, and bathing means projecting laterally from the casing for promoting a flow of gases through the portion of the casing between the opening, the outer end of the casing being provided with a water cooled cap which projects past theside wall of the casing ad acent the outer end of the outer opening and constitutes a baffle therefor.

8. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, said casing having its top and sides in the form of an inverted U and the bottom flat, a pair of openings through said bottom one outward from the filter and one inwardthereof,baffiingmeansprojecting from said casing for promoting a flow of gases through the portion of the casing between the two openings, a water cooling chamber surrounding the major portion of the outer end of the casing, and supply pipes leading through the casing inward of the end, so that the casing is cooled to a much greater extent at its outer end than along the portion which carries the sampling tube and the filter.

9. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, said casing having its top and sides in the form of an inverted U and its bottom flat, a pair of openings through said bottom, one outward from the filter and one inward thereof, baflling means projecting from said casing for promoting a flow of gases through the portion of the casing between the two openings, a water cooled cap closing the outer end of the casing, a water cooling chamber surrounding the outer end of the casing and communicating with said chamber, a supply pipe leading along the bottom of the casing to the inner end of said chamber, and a return pipe extending along the top of the casing from said chamber to the inner end of said casing.

10. In combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, said casing having its top and sides in the form of an inverted U and its bottom fiat, a pair of openings through said bottom, one outward from the filter and one inward thereof, baffling means projecting from said casing for promoting a flow of gases through the portion of the casing be tween the two openings, a water cooled cap closing the outer end of the casing, a water cooling chamber surrounding the outer end of the casing and communicating with said chamber, a pair of supply pipes extending along the bottom of the casing and discharg ing into said chamber, said pipes being welded to the side and bottom walls of the casing where they join, and a return conduit extending along the top of the casing from the chamber inward and having its side walls welded to the top wall of the casing.

11. In combination with an approximately horzontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, a closure for the outer end of the casing, and a bafiie projecting from the casing at the outer end of the outer opening.

12. I11 combination with an approximately horizontal sampling tube provided at its free end with a filter, a protecting casing surrounding the tube and extending beyond the free end thereof, a pair of openings through the casing, one located outward from the filter and the other inward thereof, a closure for the outer end of the casing,'and a'pair of baffles projecting from the casing, one at the outer end of the outer opening and the other at the outer end of the inner opening.

In testimony whereof, we have hereunto subscribed our names.

JOSEPH A. STEIN. LOUIS L. VAYDA. 

